ARTC-SVX001B-EN
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9. Symptom: Low refrigerant discharge pressure
Possible Causes
Potential Solutions
Suction shut off valve partially closed
Open valve
Insufficient refrigerant in chiller
Check for leaks. Repair and add refrigerant as needed
Compressor operating unloaded
See failure of compressor to unload or load up below
Low ambient conditions
Check condenser rating tables
Low suction pressure
See low pressure below
Condenser pressure regulating valve not properly adjusted
Refer to OEM manufacturer manual for default settings; check
equipment room ambient temperature
Fan cycling controls not properly set
Reset cut-in, cut-out settings to conform to design specifications
10. Symptom: High refrigerant discharge pressure
Possible Causes
Potential Solutions
System overcharged with refrigerant
Remove excess refrigerant
Dirty tube and fin surface
Clean with compressed air or water spray, use fin comb if fins are
bent
Non-condensables in chiller
Purge non-condensables.
Fan cycling controls not properly set
Reset fan cycle setting; replace motor controller fuse
Condensing fans not operating
Reset fan cycle setting; replace motor controller fuse
Restricted bypass line
Check valves obstructed; flush line; blow out line with dry nitrogen
gas
Discharge shut off valve partially closed
Open valve
Condenser is undersized
Check condenser rating tables with operating parameters
High ambient conditions exist
Check condenser rating tables with operating parameters
11. Symptom: Low chilled water temperature
Possible Causes
Potential Solutions
Temperature controllers set too low
Reset temperature controllers to correct design specifications
Water velocity through evaporator too low
Clean strainer; check pump, VFD, and differential pressure settings
Temperature controllers malfunctioning
Replace temperature sensor
12. Symptom: High chilled water temperature
Possible Causes
Potential Solutions
Load higher than capacity of chiller
Refer to chiller design specifications
Loss of refrigeration charge
Pressure test refrigeration system
Fouled evaporator
Reverse flush evaporator; check strainer for debris
Obstructed flow through evaporator
Reverse flush evaporator; check strainer for debris; check VFD,
pump, valves